1. Field of the Invention
The present invention relates to a laminator, and more particularly to an improvement in the structure of a film holding member which is provided near a laminate roll to laminate a film on a plate.
2. Description of the Background Art
A laminator disclosed in Japanese Patent Laying-Open No. 60-85927 is typical of laminators which employ the auto-cutting method whereby a photosensitive resist film (hereinafter, referred to as a film), for example, is successively laminated on (applied to) a plate by using a pair of laminate rolls (pressure rolls).
The schematic structure and operation of the laminator disclosed in Japanese Patent Laying-Open No. 60-85927 will be described with reference to FIGS. 13 to 15. The laminator structure disclosed in the gazette is capable of laminating a film on both sides of a plate. Since the plate structure is basically identical on the upper and lower surfaces, laminating a film on the upper surface of the plate will only be described.
In the following, the main structure of the laminator will be described with reference to FIGS. 13 to 15. The laminator which employs the auto-cutting method includes, as its main components, a pair of laminate rolls (pressure rolls) 2, 2, a film holding member 5, tacking members 1, 1, a film cutter 3 (shown in FIGS. 14 and 15), and a cutter backup 4. There is also a film 6 provided upward in the form of a film roll (not shown).
Here, film 6 means a dry photo-resist film (DRF). The dry photoresist film (DRF) has the three-layer structure of a base film, a photo-resist film, and a cover film when it is wound around the film roll. In laminating the dry photo-resist film on a plate 7 described below, only the cover film is removed and the photo-resist film plane is applied to plate 7.
Tacking members 1, 1, cutter backup 4, and film holding member 5 are connected to a negative pressure supplying apparatus (not shown). Film sucking bores 10 which can be supplied with negative pressure are provided in such contact surfaces of tacking members 1, 1, cutter backup 4, and film holding member 5 that are in contact with film 6. By properly applying negative pressure to film sucking bores 10 using the negative pressure supplying apparatus, film 6 is sucked and held as necessary.
Film cutter 3 has a rotary circular blade, and cuts film 6 by moving in the width direction of cutter backup 4 (in the direction perpendicular to the sheet) while rotating the rotary circular blade.
In the following, the operation of laminating film 6 on a plate 7 by the laminator will be described with reference to FIGS. 13 to 15.
Here, plate 7 is used for a glass plate which is used for a printed wiring board, a flat display, and so on.
Referring to FIG. 13, the front end of film 6 which is drawn out from the film roll is first brought toward the front end of plate 7 while it is sucked and held by tacking member 1 which is supplied with negative pressure. Thereafter, the front end of film 6 is pressed against the front end of plate 7 for a while by tacking member 1. Thus, tacking of the front end of film 6 on the front end of plate 7 is completed. Film 6 is tacked on plate 7 such as by pressure and heating.
Referring to FIG. 14, after tacking film 6 on plate 7, tacking member 1 stops sucking and holding film 6 and moves together with cutter backup 4 and film cutter 3 away from plate 7. Simultaneously with the operation, plate 7 on which the front end of film 6 has been tacked is transported in the direction of a pair of laminate rolls 2, 2 (in the direction of Y in the figure) by a transporting apparatus such as a roll conveyor, and directed between laminate rolls 2, 2.
Thereafter, plate 7 is sent in the direction of Y with rotation of laminate roll 2, and film 6 is sequentially laminated on plate 7 from the front end of plate 7. At this time, tacking member 1 and film holding member 5 guide film 6 to laminate roll 2 in contact with film 6.
Referring to FIG. 15, after laminating film 6 on plate 7 by a prescribed amount, tacking member 1, film cutter 3, and cutter backup 4 move at the same speed and in the same direction as film 6. In the meantime time, film cutter 3 moves in the width direction of cutter backup 4 while rotating, and cuts film 6 by the rotary blade. Thus, the rear end of film 6 is cut at right angle with respect to the sending direction of film 6, resulting in a film sheet 6A of a prescribed length.
The rear end of film sheet 6A is guided to laminate roll 2 while being sucked and held by film holding member 5 in which negative pressure is applied to film sucking bores 10. Thus, the rear end is laminated on plate 7.
In the laminator which has the above described structure and operation principle, sucking and holding of the rear end of film sheet 6A by film holding member 5 is important in evaluating the laminator performance.
Before cutting film 6, not only sucking and holding through negative pressure application to film holding member 5 but tensile force by the film roll or sucking and holding through negative pressure application to tacking member 1 gives sufficient tensile force to film 6, and thus film 6 is laminated on plate 7. In other words, film 6 is stably laminated on plate 7 without touching plate 7 before being guided to laminate roll 2.
After cutting film 6, however, tensile force is applied to the rear end of film sheet 6A only through sucking and holding by film holding member 5. The tensile force is generated by applying negative pressure to a plurality of film sucking bores 10 which are provided in such a surface of film holding member 5 that is in contact with the film.
Therefore, if film sucking bores 10 cannot be supplied with sufficient negative pressure, tensile force which is applied to film sheet 6A becomes insufficient, and the rear end of film sheet 6A comes in contact with plate 7 before being guided to laminate roll 2, thereby causing wrinkles and bubbles. Thus, stable laminating of film 6 on plate 7 cannot be implemented.
FIGS. 16 and 17 show sectional and front exploded views of film holding member 5. Film holding member 5 has a plurality of film sucking bores 10 in the contact surface 5a which is in contact with film 6, which are arranged at regular intervals at pitch P4 parallel to the sending direction of film 6 (hereinafter, referred to as the Y direction) and at pitch P3 perpendicular to the sending direction of film 6 (hereinafter, referred to as the X direction). These film sucking bores 10 are connected to the negative pressure supplying apparatus and have a structure which can be supplied with negative pressure.
The rear end of film sheet 6A immediately after being cut by film cutter 3 is sucked and held by most film sucking bores 10 of film holding member 5. Therefore, the negative pressure applied to the film sucking bores 10 of film holding member 5 maintains sufficient pressure, and film sheet 6A is supplied with sufficient tensile force. As a result, film sheet 6A is stably laminated on plate 7 in this situation without coming in contact with plate 7 before being guided to laminate roll 2.
As shown in FIG. 17, however, as the laminating operation advances and the rear end of film sheet 6A is sent to laminate roll 2, the number of film sucking bores 10 of film holding member 5 which are opened without being covered with film sheet 6A gradually increases. Therefore, negative pressure applied to film holding member 5 decreases, which makes it impossible to apply sufficient tensile force to film sheet 6A.
As a result, before film sheet 6A is guided to laminate roll 2, film sheet 6A comes in contact with plate 7 and causes winkles and bubbles. Thus, film 6a cannot be stably laminated on plate 7 till the end of laminating.
Further, film sheet 6A is not held after it moves away from film holding member 5. In order not to bring film sheet 6A in contact with plate 7 before it is guided to laminate roll 2, the distance between a portion of laminate roll 2 for pressurizing film sheet 6A toward plate 7 and film holding member 5 is preferably as small as possible.
However, laminate roll 2 is generally provided to be able to move in the thickness direction of plate 7 for the pressurizing operation. If the above described structure is provided when plate 7 does not exist, therefore, downward movement of laminate roll 2 may cause laminate roll 2 to interfere with film holding member 5.
Therefore, film holding member 5 has to be provided in advance at such a location that does not cause interference of laminate roll 2 with film holding member 5, and film holding member 5 cannot be provided near laminate roll 2.
One object of the present invention is to provide a laminator capable of stably performing the laminating operation even in laminating the rear end of a film sheet.
Another object of the present invention is to provide a laminator capable of arranging a film holding member near a laminate roll during film application in order to stably perform the laminating operation.
In one aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having film sucking bores capable of being supplied with negative pressure in such a surface that is in contact with the film, the film sucking bores being arranged more densely near the laminate roll than in other regions.
In the laminator having the above described structure, the number of film sucking bores which are open is small even if the contact area decreases between the film and the contact surface of the film holding member. Thus, reduction in the negative pressure applied to the film holding member can be suppressed and the film holding member can have sufficient film sucking bores.
As a result, even in laminating the rear end of a film, the film holding member can maintain tensile force of at least a prescribed value for the film and the laminating operation can be stably performed.
In order to implement the present invention in a more preferable manner, the structure described below is employed. For example, the film sucking bores are arranged densely even in a region near a cutter backup which is provided in the laminator. For example, the film sucking bores are arranged to be gradually dense toward the laminate roll. Further, the film sucking bores are arranged densely near the laminate roll and sparsely in other portions.
In another aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having film sucking bores capable of being supplied with negative pressure in such a surface that is in contact with the film, the opening area of each of the film sucking bores being larger near the laminate roll than in other regions.
In the laminator having the above described structure, the opening area of opened film sucking bores is small even if the contact area decreases between a film and the contact surface of the film holding member. Thus, reduction in the negative pressure applied to the film holding member can be suppressed and the film holding portion can have a sufficient opening area of the film sucking bores.
As a result, even in laminating the rear end of a film, tensile force of at least a prescribed value is maintained for the film by the film holding member and the laminating operation can be stably performed.
In order to implement the present invention in a more preferable manner, the structure described below is employed. For example, the opening area of each of the film sucking bores becomes gradually larger toward the laminate roll. Further, the opening area of each of the film sucking bores is larger near the laminate roll and smaller in other portions.
In still another aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having a film sucking bore or groove capable of being supplied with negative pressure in such a surface that is in contact with the film, the surface in contact with the film being provided with a groove extending across a direction for sending the plate.
In the laminator having the above described structure, physical resistance force increases for the film. As a result, during the laminating operation of a film, high tensile force is applied even for the same negative pressure and the same sucking bore arrangement and the laminating operation can be stably performed.
In order to implement the present invention in a more preferable manner, the groove is provided to include the film sucking bore.
In yet another aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having groove-like openings capable of being supplied with negative pressure in such a surface that is in contact with the film and extending across a direction for sending the plate.
In the laminator having the above described structure, even if the contact area decreases between the rear end of a film and the contact surface of the film holding member, provision of the groove-like openings extending across the sending direction of the plate can increase the opening area for film suction in the region. In laminating the rear end of a film, high tensile force is maintained even in the case of the same negative pressure and the laminating operation can be stably performed.
In a further aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having film sucking bores capable of being supplied with negative pressure in such a surface that is in contact with the film, the film sucking bores each including a first sucking bore and a second sucking bore which is provided coaxially with and has a larger bore diameter than the first sucking bore, and the second sucking bore being provided on the side of a surface that is in contact with the film.
In the laminator having the above described structure, the substantial opening area of the film sucking bores are increased. As a result, in laminating a film, high tensile force is maintained even in the case of the same negative pressure and the laminating operation can be stably performed.
In a further aspect of the laminator according to the present invention, a laminator to apply a film to a plate includes a laminate roll to apply the film to the plate, and a film holding member arranged near the laminate roll to guide and hold the film till a point of time immediately before applying the film to a surface of the plate and having film sucking bores or grooves capable of being supplied with negative pressure in such a surface that is in contact with the film and a disengaging apparatus for disengagement from the laminate roll with motion of the laminate roll.
In the laminator having the above described structure, the film holding member can be arranged nearer to the laminate roll when applying a film to the plate compared with a conventional laminator having a fixed film holding member. Therefore, the film can be sucked and held nearer to the laminate roll position, and thus the film can be stably laminated on the plate till the end of laminating.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.